Discovery

Lithium was discovered by Johan A. Arfvedson in Stockholm in 1817. It was
first isolated by W. T. Brande and Humphrey Davy in the nineteenth century, but was not commercially produced until 1923. Its name
comes from the Greek lithos meaning 'stone.'

Sources
of lithium

Some lithium is recovered from the mineral spodumene.
Commercial quantities of spodumene are found in a special igneous rock deposits
known as pegmatites. In pegmatites, the
liquid rock (magma) cools so slowly that crystals have time to grow very
large. The largest spodumene crystal ever found was in a pegmatite formation
in South Dakota.

Most lithium is recovered from brine, or water
with a high concentration of lithium carbonate. Brines trapped in the Earth's
crust (called subsurface brines) are the major source material for lithium
carbonate. These sources are less expensive to mine than from rock such
as spodumene, petalite, and other lithium-bearing minerals.

Uses of lithium

Lithium is used as a heat-transfer medium, because of its high specific
heat, and in various alloys, ceramics,
and optical forms of glass. Its two stable isotopes are the rarer 6Li, with
three protons and three neutrons,
and the more common 7Li, with three protons and four neutrons. 6Li is important in thermonuclear processes. Lithium stearate
is an additive to lubricating greases.

The 'lithium
problem'

Lithium is one of the few elements, along with hydrogen and helium, that
were formed in the immediate aftermath of the Big
Bang. The trouble is the amount of lithium observed in the universe
is three to four times lower than what our physics of the Big Bang predicts.
Several theories have been put forward to explain this discrepancy.

It may be that our understanding of what happened in the period immediately
after the Big Bang is wrong or incomplete. For example, it's been suggested
that dark matter may have played a role
in depleting the cosmic supply of lithium right from the start. Another
possibility is that there's some process going on in interstellar space,
yet to be fathomed, which, over billions of years, has run down the lithium
stock. Or it may be that the missing lithium is hiding deep within stars,
having been processed and moved inward in some way not yet understood.

Unfortunately, a study published in 2012 has made the lithium problem even
more acute because it predicts that some small black
holes – those weighing in at about 5 solar masses – should
act as lithium factories, so there should be even more of the stuff around
than what we're seeing.[1] In the accretion disk of such black
holes, the study finds, the temperature should be just right to trigger
nuclear fusion reactions that would produce large amounts of lithium –
in total matching that supposed to have been manufactured shortly after
the Big Bang.

Another piece of research, also published in 2012, looked at the lithium
content of gas clouds in the Small Magellanic Cloud and again confirmed that we have a missing lithium problem.[2] Although the gas has nearly as much lithium as Big Bang models they ought
to contain very much more considering how much lithium has been manufactured
inside stars since the Big Bang and then shot into space during supernova
explosions.